1.1 --- a/src/os/bsd/vm/decoder_machO.cpp Thu Jul 19 06:24:46 2012 -0700
1.2 +++ b/src/os/bsd/vm/decoder_machO.cpp Mon Jul 30 10:25:52 2012 -0400
1.3 @@ -26,6 +26,139 @@
1.4
1.5 #ifdef __APPLE__
1.6 #include "decoder_machO.hpp"
1.7 +
1.8 +#include <cxxabi.h>
1.9 +#include <mach-o/loader.h>
1.10 +#include <mach-o/nlist.h>
1.11 +
1.12 +
1.13 +bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) {
1.14 + int status;
1.15 + char* result;
1.16 + size_t size = (size_t)buflen;
1.17 + // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small,
1.18 + // __cxa_demangle will call system "realloc" for additional memory, which
1.19 + // may use different malloc/realloc mechanism that allocates 'buf'.
1.20 + if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) {
1.21 + jio_snprintf(buf, buflen, "%s", result);
1.22 + // call c library's free
1.23 + ::free(result);
1.24 + return true;
1.25 + }
1.26 + return false;
1.27 +}
1.28 +
1.29 +bool MachODecoder::decode(address addr, char *buf,
1.30 + int buflen, int *offset, const void *mach_base) {
1.31 + struct symtab_command * symt = (struct symtab_command *)
1.32 + mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB);
1.33 + if (symt == NULL) {
1.34 + DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", mach_base));
1.35 + return false;
1.36 + }
1.37 + uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */
1.38 + uint32_t nsyms = symt->nsyms; /* number of symbol table entries */
1.39 + uint32_t stroff = symt->stroff; /* string table offset */
1.40 + uint32_t strsize = symt->strsize; /* string table size in bytes */
1.41 +
1.42 + // iterate through symbol table trying to match our offset
1.43 +
1.44 + uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab
1.45 + void * symtab_addr = (void*) ((uintptr_t) mach_base + off);
1.46 + struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr;
1.47 + struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist
1.48 +
1.49 + int32_t found_strx = 0;
1.50 + int32_t found_symval = 0;
1.51 +
1.52 + for (uint32_t i=0; i < nsyms; i++) {
1.53 + uint32_t this_value = cur_nlist->n_value;
1.54 +
1.55 + if (addr_relative == this_value) {
1.56 + found_strx = cur_nlist->n_un.n_strx;
1.57 + found_symval = this_value;
1.58 + break;
1.59 + } else if (addr_relative > this_value) {
1.60 + // gone past it, use previously seen nlist:
1.61 + found_strx = last_nlist->n_un.n_strx;
1.62 + found_symval = last_nlist->n_value;
1.63 + break;
1.64 + }
1.65 + last_nlist = cur_nlist;
1.66 + cur_nlist = cur_nlist + sizeof(struct nlist_64);
1.67 + }
1.68 + if (found_strx == 0) {
1.69 + return false;
1.70 + }
1.71 + // write the offset:
1.72 + *offset = addr_relative - found_symval;
1.73 +
1.74 + // lookup found_strx in the string table
1.75 + char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx);
1.76 + if (symname) {
1.77 + strncpy(buf, symname, buflen);
1.78 + return true;
1.79 + }
1.80 + DEBUG_ONLY(tty->print_cr("no string or null string found."));
1.81 + return false;
1.82 +}
1.83 +
1.84 +void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) {
1.85 + // possibly verify it is a mach_header, use magic number.
1.86 + // commands begin immediately after the header.
1.87 + struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64);
1.88 + for (uint32_t i = 0; i < mach_base->ncmds; i++) {
1.89 + struct load_command *this_cmd = (struct load_command *) pos;
1.90 + if (this_cmd->cmd == command_wanted) {
1.91 + return pos;
1.92 + }
1.93 + int cmdsize = this_cmd->cmdsize;
1.94 + pos += cmdsize;
1.95 + }
1.96 + return NULL;
1.97 +}
1.98 +
1.99 +char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) {
1.100 +
1.101 + if (strx_wanted == 0) {
1.102 + return NULL;
1.103 + }
1.104 + char *strtab_end = strtab + tablesize;
1.105 +
1.106 + // find the first string, skip over the space char
1.107 + // (or the four zero bytes we see e.g. in libclient)
1.108 + if (*strtab == ' ') {
1.109 + strtab++;
1.110 + if (*strtab != 0) {
1.111 + DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero."));
1.112 + return NULL;
1.113 + }
1.114 + strtab++;
1.115 + } else {
1.116 + if ((uint32_t) *strtab != 0) {
1.117 + DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero."));
1.118 + return NULL;
1.119 + }
1.120 + strtab+=4;
1.121 + }
1.122 + // read the real strings starting at index 1
1.123 + int cur_strx = 1;
1.124 + while (strtab < strtab_end) {
1.125 + if (cur_strx == strx_wanted) {
1.126 + return strtab;
1.127 + }
1.128 + // find start of next string
1.129 + while (*strtab != 0) {
1.130 + strtab++;
1.131 + }
1.132 + strtab++; // skip the terminating zero
1.133 + cur_strx++;
1.134 + }
1.135 + DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted));
1.136 + return NULL;
1.137 +}
1.138 +
1.139 +
1.140 #endif
1.141
1.142
